1. Field of the Invention
The invention relates to a system for supplying steam to equipment which uses the heat of the steam for performing work and not the steam pressure. More particularly, the invention relates to a closed loop steam system which is maintained under a vacuum for continuously moving the steam through the equipment to extract heat therefrom, and to an improved condensor for effectively condensing the steam and for creating the system vacuum. The condenser also removes harmful air trapped within the condenser and prevents the air from reaching the boiler. The inherent design of the system conserves heat energy by utilizing the heat exchanged during the condensation process.
2. Description of the Prior Art
Various commercial and industrial establishments utilize equipment which requires steam for heating the equipment or parts thereof to perform work, such as dry cleaning presses, irons, etc., rather than using the pressure of the steam to perform the work as in the case of turbines, steam engines and the like. For example, commercial lanudry irons use steam for heating the irons for pressing shirts, coats and other laundry. This equipment has a series of traps to retard the velocity or passage of the steam until it is turned into a condensed state in order to extract the heat from the steam. When enough steam condenses to fill the trap, it opens permitting more steam to pass to the next trap and to discharge the the condensate from the filled trap.
These traps do not always function properly due to corrosion and sediment buildup, and consequently become clogged, decreasing the efficiency of the machine and preventing the equipment from reaching its required operatinr temperature. This reduced equipment temperature requires a longer time for each pressing or ironing operation and consequently less production. These traps reduce the velocity of the steam passing through the equipment and backs up the steam in the inlet line which results in permature condensation and lower steam temperature, and consequently less efficient steam. Likewise, this heat is being lost to the atmosphere resulting in loss of energy and increased fuel and boiler operating costs. These traps could not be removed from such equipment becuase live steam would be discharged directly into the atmosphere or directly into the boiler feed water tank and then to the atmosphere unless first condensed in a condenser. Therefore, before the traps could be removed from such equipment a condenser is required which permits the system to operate efficiently.
Condensers also effect the efficiency of steam heating systems by permitting the buildup of air within the condenser which is subsequently passed into the boiler. Water in its natural state contains five percent air and when the steam is condensed, the air is separated from the water. This air, since it is heavier than steam and lighter than water lies in the boiler at a disengaging surface. The air causes oxidation within the boiler and retards the steaming capabilities of the boiler. Therefore, it is desirable to eliminate this trapped air to increase boiler efficiency and reduce maintenance. Such oxidation is reduced by special treatment of the boiler feed water prior to its entering the boiler in existing boiler systems. This treatment increases the system operating cost considerably. Therefore it is desirable to provide a closed loop system which greatly eliminates the treatment and amount of boiler makeup water, and which provides means for eliminating such harmful air from within the boiler. Various systems have been devised for eliminating this harmful trapped air such as shown in U.S. Pat. No. 2,735,623.
Most condensers are of the "dry" type wherein the condensate and the circulating cooling water do not come in contact with each other and have a single chamber into which the steam flows to be condensed. A series of pipes pass through the chamber between inlet and outlet headers on the ends of the chamber, thereby providing only a single condensing state. It has been formed in some situations that condenser efficiency is increased by providing stages such as shown in U.S. Pat. Nos. 1,605,312 and 2,502,675.
No known steam heating system of which I am aware provides a closed loop system for use with heating equipment which enables the steam to pass directly through the equipment, which steam flow and equipment temperature is controlled by a single regulating valve by use of a multi-stage condenser which maintains a vacuum on the system and removes harmful air trapped within the condenser.